The invention relates to a device for inserting information into the finder beam path of a motion picture camera.
DE 27 34 792 C2 discloses a finder system for a film camera which has a rotating mirror shutter that is synchronized with the movement of a motion picture film, periodically interrupts the imaging beam path running from an imaging lens to the film plane, and branches off into a finder beam path such that an image of the scene to be imaged is alternately projected onto the motion picture film and deflected by the rotating mirror shutter into the finder beam path. Lying in the finder beam path at the same distance from the reflecting surface of the rotating mirror shutter as the film plane is an image plane where the finder image formed in the exposure pause for the motion picture film is imaged as a real image by a transfer optics in the plane of a field stop where it can be viewed by means of an eyepiece. Arranged in the image plane is a ground glass screen that is lit through a semitransparent mirror or beam splitter by a light source that is arranged on the opposite side of the semitransparent mirror or beam splitter, and which can be switched on in the event of unfavorable lighting conditions to light a marking arrangement provided on the ground glass screen for delimiting the recorded images.
If the film camera is used for different film formats, ground glass screens with different format indications or various manually exchangeable format masks are required for the different indications on the ground glass screen. Since the ground glass screens—as in the case of the finder system known from DE 27 34 792 C2—are part of a multipartite finder system, when exchanging the format mask or the ground glass screen provided with a format indication, it is necessary to exchange the entire multipartite system including the light source arrangement.
Reserving various multipartite finder systems, format masks or ground glass screens with different format indications is associated with substantial costs, and exchanging the multipartite finder systems including the light source arrangement, the format masks and/or ground glass screens with different format indications is associated with a substantial outlay, interventions in the interior of a motion picture camera requiring special knowledge and extreme care and being able to be carried out when a film is inserted only under specific external conditions, for example in a dark room.
In addition to a format indication on the ground glass screen of a film camera, with the aid of which a cameraman can assess a subject even in very dark recording situations, interest also attaches for the cameraman to dynamically variable data relevant to recording and to the camera, such as the film transport speed, the capacity of the rechargeable battery feeding the motion picture camera, the supply voltage, lens data, the aperture angle of an adjustable rotating mirror shutter and the like, which are inserted into the finder beam path as the subject is being viewed and enable the scene that is to be recorded to be viewed without the cameraman needing to remove his eye from the eyepiece.
JP 10010633 A discloses a finder arrangement for a still camera in the case of which there is arranged in the finder beam path a DMD (Digital Micromirror Device) chip that has a multiplicity of two-dimensionally arranged micromirror elements that consist of movably articulated micromirrors that vary the articulation angle digitally upon the application of a voltage, that is to say can be swiveled between two different alignments of the mirror surface. The DMD chip arranged in the finder beam path is driven by a DMD driver circuit, and inserts into the finder beam path either the imaging beams received via a lens or the information output by a display such that it is possible to view, through the finder either an object to be imaged or the display information. The display and the driver circuit driving the DMD chip are driven by a common CPU.
This known finder system is, however, not suitable for inserting format indications into the finder image of a motion picture camera, nor for superposing or simultaneously inserting recording-specific or camera-specific data into a finder image together with the finder beam path branched off from an imaging beam path, since the display information inserted into the finder beam path is input from the display but is not determined by the position or deflection of the micromirrors.